/Engine/Source/Runtime/Engine/Public/ParticleEmitterInstances.h
Tick sub-function that handles spawning of particles
float The SpawnFraction remaining
virtual float Tick_SpawnParticles ( float DeltaTime, [UParticleLODLevel](API\Runtime\Engine\Particles\UParticleLODLevel) * CurrentLODLevel, bool bSuppressSpawning, bool bFirstTime )